Error: replacement fee too low

[GildedHonour]

I use hardhat to deploy a bunch of smart contracts. Sometimes, and only sometimes, I'll get an exception:

Error: ERROR processing app1/deploy/Smart123.js:
Error: replacement fee too low (error={"name":"ProviderError","code":-32000,"_isProviderError":true}, method="sendTransaction", transaction=undefined, code=REPLACEMENT_UNDERPRICED, version=providers/5.5.0)

It appears that it has to do with the fact that there're multiple sequential calls, or, rather, at the same time. Right?
I use await for each one, though, and despite that the error will occur sometimes.

How to fix it?

[ricmoo]

That means you are submitting two transactions with the same nonce from the same account.

Perhaps Hardhat doesn't update the response to getTransactionCount("pending") fast enough in certain situations?

If you are trying to replace a transaction, you must increase the gas price by a non-trivial about, but I don't think that is your intention.

You would have to ask Hardhat though... :s

[GildedHonour]

I don't specify manually anything related to nonce or gas.

Should I ask Hardhat, though? There's been one issue here, in ethers-io, which is closed, with the same error. That issue didn't describe how to solve this error concreately.